Where is Smith’s Cloud Located on the Sky?

Question: What is the sky position of Smith ‘ s Cloud  many thanks.  – Bill

Answer: Smith’s Cloud is a high-velocity gas cloud gas located in the constellation Aquila (the Eagle).  The galactic coordinates for Smith’s Cloud are l = 39°, b = −13°.  The location in right ascension and declination coordinates is RA = 19h 59m and Dec = -0.3 deg.

Jeff Mangum

Posted in Constellations, Radio Astronomy | Tagged , | Leave a comment

Are There Multiple Universes?

Question: Hi! I am from Salt Lake City Utah. I’m in the sixth grade and in middle school. Middle school is really amazing and I love it. But what I love about it the most is my science teacher. His name is Mr. Krause and he is the best. he is smart funny and explains stuff in the best way! Right now we are almost done with astronomy. We started talking about the universe and I asked him this question and got a good answer but I thought I could ask you and get an even better answer? Here it is: Could we be looking at the size of the universe the wrong way? Could the universe just be one HUGE galaxy and there are multiple universes just like there are galaxies? Perhaps one day one universe will collide with another just like galaxies in our own universe.

Thanks for reading my comment! Astronomy has always interested me along with many other things about our world and its history like the past cultures. Thanks again and I hope you understand what I am trying to say.  – Kailey


Answer: That is really great that you have such an amazing science teacher!  You should be sure to tell him how much you enjoy his teaching.  As for your question about how we view the universe, let me just say that any description of the structure of the universe has always to be based on measurements.  In fact, this rule that any explanation of anything has to be based on fact applies to everything in science.  Now, since we observe stars and galaxies in our single universe, and we believe we have a pretty good understanding of how they interact and evolve, we feel confident that our observations are described very well by a single universe.  To turn that around, we can definitely say that we have no evidence for there being any additional universes other than our own.  That said, it is still possible that there are multiple universes, the evidence for which we just have not found yet.  This is a hypothetical scenario, though, that is not based on any measurements we have made.

I do hope that you continue to enjoy your science class Kailey and that Mr. Krause enjoys teaching science as much as you enjoy learning it.

Jeff Mangum

Tagged Leave a comment

Are Piercings and Tattoos Acceptable in Professional Astronomer Workplaces?

Question:  I’m interested in pursuing a career in astronomy and was wondering if, in the field of professional scientists, it is acceptable to have piercings or tattoos? I know in many professional settings it is not, so I’d like to be sure. Thanks in advance for your answer.  – Emily

Answer: Astronomy is a pretty “laid-back” field.  Few of us dress up in suits or even blazers for regular work day attire, and the dress code is considered “relaxed”.  Piercings, tattoos, inventive hair styles, etc. are all welcomed.

Jeff Mangum

Tagged Leave a comment

Do Large Stars Possess Correspondingly Large Planets?

Question: If VY Canis Majoris has a Solar System, would the planets be star-sized and the moons planet sized?  – Monte

Answer: With a mass of about 30 times that of our Sun, VY Canis Majoris is one of the largest stars known.  The size of a star, though, does not necessarily correlate with the size of the planets that might form around that star.  It is equally possible to find small planets orbiting large stars as it is to find large planets orbiting small stars.

Jeff Mangum

Posted in Exoplanets, Planets, Stars | Tagged , , | Leave a comment

How Many Years in College to be an Astronomer?

Question: I am a 14 year old girl and want to be a astronomer when I get older. I was wondering how long you would have to be in college.  – Elena

Answer: Most astronomers have doctorate (PhD) degrees in astronomy or physics.  A quick tally of the number of years that it takes to get a PhD degree can be accounted as follows:

  • 4 years for your undergraduate (bachelors) degree.
  • At least 5 years, but likely not more than 7 years, to complete your graduate studies to earn your PhD degree.

You might also be interested in visiting my Careers in Astronomy section for further information on topics relevant to those interested in pursuing careers in science, and especially astronomy.

Jeff Mangum

Tagged Leave a comment

Equation for Orbits?

Question: Why does the following equation seem to predict stable orbits around the sun as well as for moons around planets without any involvement of balancing centripetal and gravitational forces.

The following is the equation that in my investigation seems to work for planetary motion just using geometric data.

C* Vs^2*Rs^2=Vp^2*Rp

C = 8*G^0.5 = 6.548E-5

Vs  = surface velocity of rotating sphere (i.e. sun)

Rs     = radius of rotating sphere (i.e. sun)

Vp       = orbital velocity of body orbiting the sphere (i.e. planet)

Rp       = distance of orbiting body from the center of the rotating sphere.

G = Newton’s gravitational constant

– William


Answer: I am not sure how you derived this equation, but as it is not dimensionally consistent, it does not appear to be correct.  Just checking the units of the left and right side of the equation, where Newton’s gravitational constant has units (using the cgs system) cm^3/(g*s^2):

cm^3/(g*s^2) * cm^2/s^2 * cm^2 = cm^2/s^2 * cm

cm^7/(g*s^4) = cm^3/s^2

As the units for the left and right side of the equation do not equate, your equation is not correct.


Jeff Mangum

Posted in Physics, Planets | Tagged | Leave a comment

Why Do Stars Appear to Move in the Night Sky?

Question: Why do the stars in the sky appear to orbit? – Ariana

Answer: I think that you are asking why stars appear to move through the night sky from east to west in tracks that appear to be centered on the North Star.  These apparent star tracks are in fact not due to the stars moving, but to the rotational motion of the Earth.  As the Earth rotates with an axis that is pointed in the direction of the North Star, stars appear to move from east to west in the sky.

Jeff Mangum

Posted in Celestial Events, Stars | Tagged , | Leave a comment

Can Black Holes Eat One Another?

Question: Ok so say the universe gets to a point where every black hole consumes everything including each other until your left with a single black hole. Or would this not be possible due to the universe ever expanding and just the vastness of the universe ? Just a thought.  – Danny

Answer: Space is actually a pretty empty place on average.  The WMAP cosmic microwave background probe measurements indicated that there are on average about 6 protons per cubic meter in the Universe.  I believe therefore that the possibility of black holes even interacting with each other is pretty small.

Jeff Mangum

Tagged Leave a comment

A Career in Astronomy?

Question: Hi, would you recommend someone to study astronomy from your current work experience? and why.  – Lindokuhle

Answer: I suggest that you look over the “Careers in Astronomy” posts elsewhere in this blog for some information regarding careers in astronomy.  There are many reasons to pursue a career in the sciences, and the decision to do so really rests on your personal desires and interests.

Jeff Mangum

Tagged Leave a comment

How to Find the Southern Cross from Panama

Question: Hello…I am visiting Panama, and live at 52degrees N in central Canada.  I heard that I should be able to see the Southern Cross from here.  At what time is best to see it, and since there is a full moon, will this affect finding it.  – Harry

Answer: I believe that you are asking how you can view the Southern Cross (in the constellation Crux) from Panama.  This time of year Crux rises in the south, just to the east of due-south point on the horizon, around 23:30 (just before midnight) and transits around 04:00 in the morning.  Crux sets around 08:00, which is an hour or so after sunrise.  As it is currently very close to a full Moon, you will not be able to avoid competing with it.

Jeff Mangum

Tagged Leave a comment